The Haber Process
Year 11 (IGCSE) ⚗️ Chemical Reactions Explain N₂ + 3H₂ ⇌ 2NH₃; justify industrial conditions using equilibrium.
🏭 The Haber Process
The Haber process makes ammonia from nitrogen and hydrogen — essential for fertilisers and nitric acid.
Reaction
$$\text{N}_2(g) + 3\text{H}_2(g) \rightleftharpoons 2\text{NH}_3(g) \quad \Delta H = -92 \text{ kJ/mol}$$Sources: N₂ from fractional distillation of liquid air; H₂ from steam reforming of natural gas.
⚖️ Industrial Conditions
| Condition | Value | Reason |
|---|---|---|
| Temperature | ~450°C | Compromise: rate vs yield (exothermic → lower T = more yield but too slow) |
| Pressure | ~200 atm | 4 mol → 2 mol gas (high P → right shift); higher P = expensive/dangerous |
| Catalyst | Iron | Increases rate; equilibrium position unchanged |
| Recycle N₂/H₂ | Yes | Improves overall yield; economical |
🧮 Haber Calculations
1 mol N₂ reacts at 15% yield. Mass of NH₃?
Theoretical: 1 mol N₂ → 2 mol NH₃ = 34 g
Actual: 34 × 0.15 = 5.1 g
Theoretical: 1 mol N₂ → 2 mol NH₃ = 34 g
Actual: 34 × 0.15 = 5.1 g
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Interactive Demonstration — The Haber Process
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🏭 Haber Process Calculator
N₂ + 3H₂ ⇌ 2NH₃ — stoichiometry and yield calculations.